A couple of weeks ago, we went for a bat walk in Sutton Park. Equipped with warm clothes and torches we searched for bats in the dark autumn evening using bat detectors. The rain was drizzling but luckily the bats still came out to feed.

Bats are mammals and they are the only mammal who is capable of natural flight. Bats find their food and water by using echolocation. As a bat flies, it makes loud shouting sounds, which are too high for most humans to hear. The echoes they get back from their shouts give them information about anything that is ahead – echolocation.

Just after sunset, bats come out from their roosts and make test fights where they send out special signals. A bit later, you can hear their feeding buzz when they catch something. A bat eats a lot of insects – it is estimated that a pipistrelle bat can eat around 3 000 insects in a single night.

Different bat species use different frequencies and by using a bat detector you an not only hear the high sounds but it also helps with the identification. We heard pipistrelle bats, which are the most common bats in the UK. We also heard soprano pipistrelle bats who look similar to the pipistrelle but has a higher frequency echolocation call.

Bats can by using their echolocation tell how far away something is by how long it takes for the sound they send out to return to them. Even though it is great to use a bat detector it is even better to use a special app to help with the identification. Our detectors picked up brown long-eared bats and Daubenton’s Bats. The brown long-eared bats have huge ears that provide them with exceptional hearing – they can even hear a ladybird walking on a leaf below them when they are flying around. Bats can also detect insects and frogs that are hiding motionless on a leaf.

Over a little lake, we saw some Daubenton’s bats searching for insects. They were flying close to the surface of the water looking for insects. In the dark evening, their whitish belly helped with the identification.

Of course, going on a bat walk is a great way to spark ideas. Bats have provided inspiration for and flying robots and a vibrating ultrasonic cane to help blind people detect obstacles. Their skin has attracted attention since they have a network of hair-thin muscles in their wing skin to control the stiffness and shape of their wings. This could help engineers to design aeroplanes or even a cleaning mop!

What ideas do you get when you think of these magnificent flying creatures?

Photos:

Newborn Common Pipistrelle (Pipistrellus pipistrellus, a foundling) sitting on the back of a hand. Size: about 3 cm.